Fetal Flaw

The abortion politics of new prenatal tests.

Today, if you’re pregnant with a defective fetus, you won’t know about the problem till you’re well along. At 10 to 12 weeks, you can get chorionic villus sampling, which involves extracting tissue from the placenta by going through your abdomen or inserting a tube through your cervix. At 15 weeks or so, you can get amniocentesis, which involves sticking a long needle through your belly to draw amniotic fluid. Both tests are uncomfortable, and in one case out of every 100 to 200, they cause a miscarriage.

Will Saletan writes about politics, science, technology, and other stuff for Slate. He’s the author of Bearing Right.

That’s now changing, thanks to noninvasive prenatal testing (NIPT). As Mara Hvistendahl explained recently in Slate, companies are developing tests that can estimate the risk of a defective pregnancy from fetal DNA in the mother’s own blood, extracted by a regular needle from her arm, like any other blood draw. That means less risk of miscarriage, less stress, less discomfort, less hassle, and lower cost. It also means earlier detection. This week, at a conference at Stanford Law School, companies working on the technology said their tests could screen for defects at 10 weeks. But informally, the expected threshold for NIPT is seven to eight weeks, and possibly five.

What’s going to happen to prenatal testing in this country when you can get it earlier, cheaper, and more easily? What will happen to the abortion rate and the population of families affected by, say, Down syndrome? Will pro-lifers and disability groups freak out? Will states restrict the new tests?

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I don’t think so. I’ve been looking at recent polling data, as well as the science and practice of prenatal testing. The interests lined up behind NIPT are formidable: parents, disease lobbies, biotech and medical companies, insurers, and governments that fund health care. And on the other side, pro-lifers will have a much harder time fighting NIPT than they’ve had fighting abortion.

The problem for pro-lifers is that prenatal testing doesn’t work this way. It combines some issues and separates others in ways that confound moral distinctions. To begin with, there’s an obvious medical and business logic to screening for many conditions in a single test. Once you’ve assembled fetal DNA from fragments in the mother’s blood, you might as well check it for Down syndrome as well as cystic fibrosis. So while some people might condone testing for one disease but not the other, it isn’t clear how you’d write, pass, or enforce a law to impose that distinction.

Nor is it clear how you’d impose a distinction between one purpose and another. Take sex selection. The EPPC poll, like others, shows overwhelming opposition to permitting abortions of fetuses just because they’re female. Yesterday, a majority of the U.S. House of Representatives voted to outlaw such abortions. But doctors test for fetal sex all the time. They do it because some families carry X-linked disorders, which produce disease in boys, since males don’t inherit a second X chromosome to counteract the first one. If sex is a medically legitimate trait to test for, how will you police which women can be told they’re carrying girls, and which can’t? And once they’re told, how can you connect that disclosure to their subsequent decisions? It’s not like they’re all going to announce to an abortion provider that they want the fetus out because it’s a girl.

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Look closely at the question in the EPPC poll. It doesn’t ask whether testing should be allowed for nonfatal conditions. It asks whether abortions should be allowed based on the test results. Why? Because if you don’t mention abortion, Americans don’t object to the tests. In a 2004 survey by the Genetics and Public Policy Center, 60 percent of respondents approved of prenatal genetic testing for diseases that wouldn’t even show up in the fetus till it reached adulthood. Fifty-one percent approved of testing for fetal sex. In every scenario, support for testing fetuses exceeded support for testing pre-implantation embryos. That’s a pretty clear sign that the respondents weren’t thinking about abortion.

The separability of testing from abortion, coupled with the bundling of testable diseases and the ambiguity of how the findings will be applied, makes moral regulation of prenatal testing a logistical nightmare. It puts pro-lifers in the politically untenable position of opposing information and health care, not just abortion.

Ugly as that episode was, an attack on NIPT could get uglier. Santorum was challenging amniocentesis, which takes place in the second trimester. NIPT takes place in the first trimester. Morally, this makes NIPT far more palatable, since the fetus is less developed. Politically, it puts pro-lifers in the awkward position of opposing a technology that could replace second-trimester abortions with first-trimester abortions. Last year, Gallup found that while only 24 percent of Americans thought abortion should be legal in the second trimester, 62 percent thought it should be legal in the first trimester. An attack on NIPT would defy this consensus that earlier is better. And it would leave pro-lifers with the task of explaining why women should be consigned to tests that produce a measurable rate of miscarriage.

That doesn’t mean pro-lifers can’t or shouldn’t do anything about NIPT. The availability of easier, cheaper, earlier tests will almost certainly increase the abortion rate. Pro-lifers might succeed in regulating counseling or insurance practices so that ambivalent women don’t feel pressured to abort. But the best way to separate testing from abortion is to push the technology forward so that we're fixing defective embryos and fetuses, not just discarding them. Who could be against that?